Triphenyl monomers suitable for microstructured optical films

Abstract

Optical films are described having a polymerized microstructured surface that comprises the reaction product of a polymerizable resin composition comprising at least one polymerizable ethylenically unsaturated triphenyl monomer. Also described are certain triphenyl(meth)acrylate monomers and polymerizable resin compositions.

What is claimed is: 
     
       1. An optical film comprising a base layer and a polymerized microstructured surface comprising a linear array of regular right prisms wherein the polymerized microstructured surface comprises the reaction product of a polymerizable resin composition comprising at least one triphenyl monomer having the general structure 
       
         
           
           
               
               
           
         
         wherein R2 is independently H, methyl, or a substituent comprising a (meth)acrylate group and at least one R2 is a substituent comprising a (meth)acrylate group; 
         X is independently halogen, aryl, or a C 2  to C 12  alkyl group; and 
         and p is 0 to 5. 
       
     
     
       2. The optical film of  claim 1  wherein p is 0. 
     
     
       3. The optical film of  claim 1  wherein R2 is independently a (meth)acrylate substituent selected from 
       
         
           
           
               
               
           
         
         wherein Q is O or S; 
         L is a C 2  to C 6  alkylene group optionally substituted with a one or more hydroxyl groups; 
         n ranges from 0 to 10; 
         R1 is H or CH 3 ; and 
         R3 is hydrogen, methyl, aryl, or a C 2  to C 12  alkyl group. 
       
     
     
       4. The optical film of  claim 3  wherein Q is O. 
     
     
       5. The optical film of  claim 4  wherein L is C 2  or C 3  and n is 1. 
     
     
       6. The optical film of  claim 1  wherein X is independently halogen or a C 2  to C 12  alkyl group. 
     
     
       7. The optical film according to  claim 1  wherein the triphenyl monomer is a mono(meth)acrylate. 
     
     
       8. The optical film according to  claim 1  wherein the triphenyl monomer is a di(meth)acrylate. 
     
     
       9. The optical film according to  claim 1  wherein the triphenyl monomer is a tri(meth)acrylate. 
     
     
       10. The optical film of  claim 9  wherein the triphenyl monomer has the structure 
       
         
           
           
               
               
           
         
       
     
     
       11. The optical film of  claim 9  wherein the triphenyl monomer has the structure 
       
         
           
           
               
               
           
         
       
     
     
       12. The optical film according to  claim 1  wherein the polymerizable resin composition comprises
 up to 50 wt-% of one or more triphenyl(meth)acrylate monomers; and 
 25 wt-% to 75 wt-% of one or more multi(meth)acrylate monomers or oligomers having at least two polymerizable (meth)acrylate groups. 
 
     
     
       13. The optical film of  claim 12  wherein the multi(meth)acrylate monomer comprises one or more bisphenol A (meth)acrylates, aromatic epoxy(meth)acrylates, and mixtures thereof. 
     
     
       14. The optical film of  claim 1  wherein the polymerizable resin further comprises an aromatic monofunctional (meth)acrylate monomers comprising a phenyl, cumyl, biphenyl, or napthyl group. 
     
     
       15. The optical film according to  claim 1  wherein the polymerizable resin composition comprises less than 1 wt-% total of chlorine, bromine, or mixtures thereof. 
     
     
       16. The optical film according to  claim 1  wherein the polymerizable resin is free of inorganic nanoparticles. 
     
     
       17. The optical film according to  claim 1  wherein the polymerizable resin comprises at least 10 wt-% of surface modified inorganic nanoparticles. 
     
     
       18. The optical film of  claim 17  wherein the inorganic nanoparticles have a refractive index of at least 1.68. 
     
     
       19. The optical film of  claim 17  wherein the inorganic nanoparticles comprise zirconia. 
     
     
       20. The optical film according to  claim 1  wherein the optical film is a brightness enhancing film having a single sheet gain of at least 1.59.